The only risks for HIV in adults are:
1) Having unprotected anal or vaginal sex, or
2) sharing intravenous needles with IV drug users.
You CANNOT get HIV or any STDs when one person is wearing underwear. The only way to get HIV sexually is by inserting your penis into a vagina or anus without a condom on.
You also cannot get HIV or any STDs from your hand, no matter what your hand has touched.
You had zero risk for HIV or any STDs, but if you had had a risk, washing your penis would not stop you from being infected.
And might’ve touched my penis with the hand I use to touch her clit while washing it